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How to count the frequency of the elements in an unordered list?
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The python groupby creates new groups when the value it sees changes. In this case 1,1,1,2,1,1,1] would return [3,1,3]. If you expected [6,1] then just be sure to sort the data before using groupby.
– Evan
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What is the most efficient way to store a list in the Django models?
Currently I have a lot of python objects in my code similar to the following:
12 Answers
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Reading specific lines only
... 29:
break
fp.close()
Note that i == n-1 for the nth line.
In Python 2.6 or later:
with open("file") as fp:
for i, line in enumerate(fp):
if i == 25:
# 26th line
elif i == 29:
# 30th line
elif i > 29:
break
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How to print a linebreak in a python function?
I have a list of strings in my code;
8 Answers
8
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How do I check if a string is a number (float)?
...e best possible way to check if a string can be represented as a number in Python?
33 Answers
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Convert UTC datetime string to local datetime
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If you don't want to provide your own tzinfo objects, check out the python-dateutil library. It provides tzinfo implementations on top of a zoneinfo (Olson) database such that you can refer to time zone rules by a somewhat canonical name.
from datetime import datetime
from dateutil import t...
Difference between two dates in Python
...imedelta object and the documentation makes not mention of it either (docs.python.org/2/library/datetime.html).
– user1761806
Jun 26 '17 at 10:46
4
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Check if multiple strings exist in another string
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any() takes an iterable. I am not sure which version of Python you are using but in 2.6 you will need to put [] around your argument to any(). any([x in str for x in a]) so that the comprehension returns an iterable. But maybe later versions of Python already do this.
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How do I get a list of column names from a psycopg2 cursor?
...umn labels directly from the selected column names, and recall seeing that python's psycopg2 module supports this feature.
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TypeError: method() takes 1 positional argument but 2 were given
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In Python, this:
my_object.method("foo")
...is syntactic sugar, which the interpreter translates behind the scenes into:
MyClass.method(my_object, "foo")
...which, as you can see, does indeed have two arguments - it's just...